There is growing evidence that millions of adults have gained insurance coverage under the Affordable Care Act, but less is known about how access to and affordability of care may be changing. This study used data from the Health Reform Monitoring Survey to describe changes in access and affordability for nonelderly adults from September 2013, just prior to the first open enrollment period in the Marketplace, to March 2015, after the end of the second open enrollment period. Overall, we found strong improvements in access to care for all nonelderly adults and across income and state Medicaid expansion groups. We also found improvements in the affordability of care for all adults and for low- and moderate-income adults. Despite this progress, there were still large gaps in access and affordability in March 2015, particularly for low-income adults.